The additional information you need is the density of isopropyl alcohol. The density of a substance is a measure of the mass per unit volume. It is often given in the units of grams per mL. The listed density of isopropyl alcohol is 0.786 g/mL. In other words, every one mL of isopropyl alcohol contains 0.786 grams of mass. If you multiply the density times the volume of isopropyl alcohol you can get the total mass of the sample:
0.786 g/ml * 9.50 mL = 7.467 grams isopropyl alcohol.
When you have the volume and the density of any liquid you can readily find the mass of the liquid by multiplying the two as shown above.
Density = Mass/Volume
=> Density x Volume = Mass
The density of rubbing alcohol is 0.786 g/mL. Therefore, a 9.50 mL sample has a mass calculated as follows:
0.786 g/mL x 9.50 mL = 7.467 g